KR20050010712A - Electric machine with improved stator fixing - Google Patents

Abstract

PURPOSE: An electric machine having a well-fixed stator is provided to be operable in high temperature by excluding an adhesive between a housing and a stator. CONSTITUTION: An electric machine having a well-fixed stator includes a housing(2), a stator(4), and a rotor. The housing includes at least one region which is exposed inside the housing to fix the stator. The stator is fixed by the at least one regions and an inner surface of the housing.

Description

ELECTRIC MACHINE WITH IMPROVED STATOR FIXING

The present invention relates to an electrical machine comprising a housing, a stator and a rotor, and more particularly to a better fixing of the stator to the housing.

Electric machines are used as motors or generators in many fields, such as, for example, electric auxiliary drives of vehicles. In permanent excitation electric machines, in mass production, the stator is generally attached to a housing (pot). In general, the stator consists of a plurality of stacked individual plates stacked on each other or pressed against each other through protruding protrusions on one side and stamped blind holes on the opposite side. Since the stator is made of perforated plates, the stator includes sharp burrs at its perforated edges. This indicates that when attempting to pressurize the stator stack into the cylindrical housing, the sum of manufacturing tolerances requires on the one hand the greatest pressing force but on the other hand the metal chip can be separated from the stir burr of the stator during pressurization. This chip, on the one hand, causes deformation of the components, and on the other hand, free chips in the electric machine may cause premature failure. Thus, in recent years, the stator is engaged with the housing of the electric machine by attachment to ensure sufficient process reliability.

In comparison, an electric machine according to the invention comprising the features of claim 1 comprises the advantage that the attachment coupling between the housing and the stator can be omitted. This allows the electric machine according to the invention to be operated in a higher temperature region by the absence of adhesives. According to the invention, a mechanical and thermally stable bond is formed between the housing of the electric machine and the stator. Here, the housing comprises at least one inwardly protruding region, such that the stator is secured by an inwardly protruding region in the interior of the housing. Since the inwardly projecting area is locally defined on the inner jacketed surface of the housing, the stator can be secured in the jacketed inner area of the housing. In addition, a pressure coupling between the stator and the housing produces a substantially constant pressing force over a large tolerance range. According to the invention, larger tolerances can be accommodated than in conventional joining methods by attachment. In addition, according to the present invention, it is not required to cut and finish the stator stack or stator plate so that the chips are finally removed or the stator tolerance is reduced.

The subject matter of the dependent claims includes preferred embodiments of the invention.

Preferably, the housing includes two inwardly projecting areas. At this time, the stator is fixed in the housing by two inwardly protruding regions of the housing and the inner jacket surface. Thus, the stator is securely fixed in three sections along its outer circumference.

According to another preferred embodiment of the present invention, the stator is fixed only by an area projecting inwardly of the housing.

Particularly preferably, the inwardly projecting areas are spaced from one another at the same width along the periphery of the housing. This achieves a uniform distribution of the clamping force onto the stator.

According to another preferred embodiment of the present invention, a jacketed intermediate element is preferably disposed between the stator and the inner jacket area of the housing, which completely surrounds the stator. Through this, the stator can first be introduced into the jacketed intermediate element and then together with the jacketed intermediate element into the housing of the electric machine. This can reliably reduce chip generation during the pressing process.

Preferably, the jacketed intermediate element comprises a region overlapping in the peripheral direction. According to another preferred embodiment of the present invention, the jacketed intermediate element is formed to include a bond edge rather than an overlapping area. The jacketed intermediate elements can be joined to one another, for example by welding, at overlapping regions or at the joining edges.

In order to simplify the introduction of the jacketed intermediate element into the housing, the jacketed intermediate element preferably comprises a tapered region, in particular a conical region.

Particularly preferably, the inwardly projecting area is made through a groove formed in the outer area of the housing. Preferably, the grooves are provided with grooves arranged in the axial direction of the housing, in particular preferably over the entire axial length of the stator or arranged offset from one another in a plurality of shorter, continuous or peripheral directions.

Preferably the jacketed intermediate element is made of spring steel.

Also preferably, the region projecting into the interior of the housing is cured or an additional cured layer is applied on the region projecting into the interior of the housing. Curing can be effected, for example, via nitriding, spark hardening or induction hardening, preferably only the protruding areas are hardened, not the entire inner surface of the housing.

Particularly preferably, the housing of the electric machine is formed in a port shape.

Preferably, the electric machine according to the invention is an EC-motor or an EC-generator, particularly preferably in a vehicle, for example as an auxiliary drive for a particularly comfortable device such as an electric window lift, an electric sliding loop, a wiper motor or the like. Used. This allows the manufacturing advantages of the electrical machine according to the invention to be used particularly well by mass production, resulting in a significant cost advantage over the prior art.

DESCRIPTION OF THE EMBODIMENTS An embodiment of an electric machine according to the present invention is described below in connection with the accompanying drawings.

1 is a schematic longitudinal sectional view of an electric machine according to a first embodiment of the present invention,

2 is a schematic cross-sectional view of the electric machine shown in FIG. 1,

3 is a schematic cross-sectional view of an electric machine according to a second embodiment of the present invention,

4 is a schematic cross-sectional view of an electric machine according to a third embodiment of the present invention,

5 is a schematic cross-sectional view of an electric machine according to a fourth embodiment of the present invention,

6 is a schematic cross-sectional view of an electric machine according to a fifth embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

1: electric machine

2: housing

3: protruded area

4: stator

5: rotor

1 and 2, an electric machine 1 according to a first embodiment of the present invention is described below. The electric machine 1 is an EC-motor used in a vehicle. 1 is a cross-sectional view along the line I-I of FIG. 2.

The electric machine 1 comprises a housing 2, a stator 4, a rotor shaft 5 comprising a permanent magnet 6 arranged thereon and an electrical plug type connection 8. The rotor shaft is supported on two bearings 7 at their opposite ends. The stator 4 comprises an insulation, a sensor and a coil in a known manner. The housing 2 is formed in a port shape and is closed by the loop element 13 on its open side. The torque of the rotor shaft 5 can be removed through the teeth 14 protruding from the electric machine 1 and integrally formed on the rotor shaft.

2 shows in detail the connection between the housing 2 and the stator 4. For a better overview the coil of the stator 4 is not shown in FIG. 2. As can be seen in FIG. 2, a plurality of longitudinal grooves are formed on the outer periphery of the housing 2, such that an inwardly protruding region 3 is formed on the inner jacket periphery of the housing 2. do. In the embodiment shown in FIGS. 1 and 2, exactly nine protruding regions 3 are formed. The protruding region 3 extends over the entire length of the cylindrical part of the housing 2 and can simply be formed simultaneously in the manufacture of the housing 2. The stator 4 is held through the protruding region 3 of the housing 2, which acts like a spring element to secure the stator 4 to the housing 2. The amount of fixation force is set such that the stator cannot be twisted or displaced axially with respect to the housing 2. The protruding regions 3 are each spaced apart from each other by the same width on the periphery of the housing 2, so that a uniform holding force is applied onto the stator 4.

Thus, through the form of the housing 2 according to the invention the stator 4 can be fixed without being attached to the housing 2. The stator plate lamination can be finished by the construction of the housing 2 according to the invention, since no shortcomings arise in the operation of the electric machine, for example a central error, and larger tolerances can be accommodated through the housing 2. Need not be. Since the housing 2 is preferably made of spring steel plates, the electric machine according to the invention can be operated as a machine in which the stator is attached to the housing in the higher temperature region. The electric machine 1 according to the invention can be manufactured or assembled more quickly and cheaply by omitting the attachment step.

3 shows an electric machine according to a second embodiment of the present invention, in which the same or functionally identical parts are denoted by the same reference numerals as in the first embodiment.

Unlike the first embodiment, in the second embodiment an additional jacketed intermediate element 9 is arranged between the housing 2 and the stator 4. The jacketed intermediate element 9 essentially comprises a tubular structure and completely surrounds the stator 4. For assembly of the jacketed intermediate element 9 preferably the stator 4 is first introduced into the jacketed intermediate element 9, and then the jacketed intermediate element 9 together with the stator 4 in the housing 2. Pressurized into In this way, chipping can be completely prevented, for example, by eliminating the cutting while pressing the stator into the housing. The stator 4 is no longer in direct contact with the housing 2. Thus, the jacketed intermediate element 9 is preferably used for electrical machines in which failure prevention should be most assured. Otherwise, the second embodiment shown in FIG. 3 corresponds to the first embodiment.

Hereinafter, a third embodiment of the present invention will be described with reference to FIG. 4, wherein like parts are denoted by the same reference numerals as in the first embodiment.

The third embodiment, like the second embodiment, comprises a jacketed intermediate element 9. However, unlike the second embodiment, in the third embodiment only two inwardly protruding regions 3 are formed in the housing 2. As can be seen in FIG. 4, the stator 4 is fixed between the two inwardly protruding regions 3 of the housing 2 and the inner jacket region 10. The two inwardly projecting regions 3 are offset from one another along the periphery over approximately 120 °, providing a uniform holding force through the interior region 10 and the projecting region 3.

In figures 5 and 6 there is shown a fourth or fifth embodiment comprising a jacketed intermediate element 9 respectively. The jacketed intermediate element 9 is made in a rectangular plate shape. The embodiment shown in FIG. 5 shows an overlapping region 11 in which the two ends of the essentially cylindrical intermediate element 9 are located opposite in the circumferential direction. The overlap is arranged in the region between the two protruding regions 3 of the housing. This does not cause adverse effects on the holding forces provided by the protruding areas 3.

The embodiment shown in FIG. 6 likewise comprises a jacketed intermediate element 9, but instead of overlapping regions a joining edge 12 is formed between the ends of the intermediate element 9 located in the circumferential direction. The joining edges 12 smoothly connect the peripheral ends of the intermediate elements 9.

It can be seen that the peripheral ends can be fixedly connected to one another, for example by welding. The peripheral ends can be combined, for example, by laser welding or by attachment. However, it is not necessary to fixedly combine the peripheral ends of the intermediate elements 9 with each other.

According to the present invention, the electric machine has the effect of omitting the attachment coupling between the housing and the stator.

Claims (11)

In an electrical machine comprising a housing (2), a stator (4) and a rotor (5), The housing (2) is characterized in that it comprises at least one inwardly projecting area (3) for securing the stator (4) inside the housing (2). 2. The housing (2) according to claim 1, wherein the housing (2) comprises two inwardly protruding regions (3), wherein the stator (4) has two inwardly protruding regions (3) and an inner surface area ( An electric machine, which is characterized in that it is fixed to the housing (2) by means of 10). The electric machine according to claim 1, wherein the stator (4) is fixed only by an area (3) projecting inwardly of the housing (2). 4. The electric machine according to claim 1, characterized in that the inwardly projecting areas (3) are spaced apart from each other by the same width along the periphery of the housing. 5. The electric machine according to claim 1, characterized in that a jacketed intermediate element is arranged between the stator and the housing. 6. 6. Electric machine according to claim 5, characterized in that the jacketed intermediate element completely surrounds the stator (4) and comprises overlapping regions (11) or bonding edge regions (12). The electric machine according to claim 1, characterized in that the jacketed intermediate element (9) comprises a tapered region, in particular a cone-shaped region. 8. The inwardly protruding region 3 extends over the entire axial length of the stator 4 in the axial direction XX of the electric machine. 9. , Electromechanical. 9. The curable layer according to claim 1, wherein the region 3 projecting inwardly of the housing is cured or a cured layer is applied on the region 3 projecting inwardly of the housing. Made, electric machine. 10. Electric machine according to any one of the preceding claims, characterized in that the housing (2) is formed in a port shape. The electric machine according to claim 1, wherein the winged electric machine is an EC-motor or an EC-generator.